CVE-2026-53943
Ghost: Cache-poisoning XSS in Ghost frontend via x-ghost-preview header
Description
Ghost is a Node.js content management system. From until 6.37.0, when Ghost is behind a shared caching layer that results in cached content being shared between different visitors, an unauthenticated user could send an x-ghost-preview header that altered the rendered frontend response. In affected cache configurations, that response could be stored and served to subsequent visitors requesting the same page, allowing cache poisoning of request-specific preview output. When running Ghost's frontend and admin panel on the same domain this could be used to take over staff user accounts. When running these on different domains staff accounts have no exposure. This vulnerability is fixed in 6.37.0.
How to fix CVE-2026-53943
To remediate CVE-2026-53943, upgrade the affected package to a fixed version below.
- —upgrade to 6.37.0 or later
- —upgrade to 6.37.0 or later
Is CVE-2026-53943 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- >= 4.0.0, < 6.37.0
- >= 4.0.0, < 6.37.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |